Requirements for hurricane track
and intensity guidance
Presented By: Vijay Tallapragada and Sam Trahan (NWS/NCEP)
Contributors: HWRF Team at EMC, NHC & HFIP
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Operational System Attribute(s)
System Name
Acronym
Areal Coverage
Horz
Res
Cycle
Freq
Fcst
Length
(hr)
Hurricane Weather Research and
Forecast Modeling System
HWRF
All global tropical 18/6/
cyclone basins,
2 km
max. 7 storms,
on demand by
NHC/CPHC/JTWC
4
126
Message Passing Interface
Princeton Ocean Model for
Tropical Cyclones
MPIPOMTC
North Atlantic &
North Eastern
Pacific
4
126
6 km
System Data Assimilation or Initialization Technique
System
Attributes
HWRF
One-way Hybrid Global EnKF – Regional 3DVAR for North Atlantic
basin. For Tail Doppler Radar data assimilation, global ensembles are
replaced by 40-member high-resolution HWRF ensembles
MPIPOM-TC
Feature based initialization of loop current, cold/warm core eddies and
TC induced cold wake in the North Atlantic; GDEM Climatology based
initialization for North Eastern Pacific
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Why System(s) are Operational
 Primary stakeholders and requirement drivers
•
•
NHC, CPHC, JTWC and NWS PR
Various WFOs, WMO RSMCs and various international TC forecast agencies
 What products are the models contributing to?
•
Tropical Cyclone Track, Intensity, Structure, Size, Swaths of Maximum Wind and Storm Total
Rainfall, Synthetic Satellite Imagery and Simulated Radar Reflectivity, hourly high-res winds
 What product aspects are you trying to improve with your development plans?
•
Tropical Cyclone Track, Intensity, Rapid Intensity Changes, Structure, Size, QPF, landfall impacts
(storm surge, significant wave heights, rainfall, flooding and inundation)
 Top 3 System Performance Strengths
• The only high-resolution cloud-resolving non-hydrostatic ocean-coupled model operating at 2km
•
•
resolution, specifically designed for tropical cyclone forecast guidance
The only operational model capable of ingesting aircraft reconnaissance data (inner-core Tail
Doppler Radar and dropsondes) in real-time
Top performer for track and intensity forecast guidance for all global tropical cyclones through
their life cycle (including areas of investigation) to NHC, CPHC and JTWC
 Top 3 System Performance Challenges
•
•
•
•
Forecast performance for Rapid intensity changes (RI/RW)
Representation of multi-scale interactions and scale-aware physics
Assimilation of all-sky radiance data and all manned/unmanned aircraft reconnaissance data
Coupling to Waves and Hydrology
3
System Evolution
Over the Next 5 Years
 Major forcing factors
•
•
•
•
NHC Track and Intensity GPRA goals: Saving lives & property through reduced errors and
increased accuracy of tropical cyclone forecasts
Continuous forecast improvement goals targeted by HFIP and NGGPS
Reliable and accurate high-resolution forecast guidance for significant weather events
associated with tropical cyclones
Comprehensive forecast solutions for all aspects of tropical cyclones from genesis through
dissipation, including downstream applications
 Science and development priorities
•
Continuous improvements to model resolution, dynamics and physics, modeling storm-storm
and multi-scale interactions; Assimilation of all-sky radiance and all available data; Improved
air-sea-wave-land-hydrology coupling and High-resolution ensembles
 What are you top challenges to evolving the system(s) to meet stakeholder
requirements?
•
Rapid transition of scientific research and developments supported by HFIP and NGGPS;
Computational resources; Data collection, quality control and real-time transmission,
Technological and engineering aspects of, appropriate representation of scale-aware and
stochastic physics, ensemble strategies
 Potential opportunities for simplification going forward
• Transition to NMMB/NEMS  Unified mesoscale models for convective scale forecasts
• unified non-hydrostatic global model with high-resolution nests coupled to ocean, waves, land
and hydrology
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Top 3 Things You Need
From the UMAC
1. Strategies for unified regional (meso-scale) models in the NEMS framework
• Be able to meet the performance of current operational HWRF
• Be able to provide TC-related products for all global tropical cyclones
• Accommodate future development strategies including coupling to ocean,
waves, land, surge and hydrology
• Retain and expand community interactions fostered by HFIP
• Flexible options for inner-core data assimilation
• Enable future ensemble strategies and potential genesis and 7-day
intensity forecasts
2. Strategies for unified global model with multiple moveable nests
• Be able to meet the performance of current operational HWRF
• Be able to provide TC-related products for all global tropical cyclones
• Accommodate future development strategies including coupling to ocean,
waves, land, surge and hydrology
• Retain and expand community interactions fostered by HFIP and NGGPS
3. Strategies for serving the next-generation needs of operational tropical
cyclone forecasters
• Expand the products to include deterministic and probabilistic forecast
guidance on genesis, rapid intensity changes, size, structure, storm
surge, rainfall, flooding and inundation and warn on forecasts
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